Irrigation lavage

ABSTRACT

An irrigation lavage is useful, for example, in wound debridement. It serves to deliver pulses of fluid under pressure. It includes a housing that defines a chamber in which an electric motor is mounted so as to have a drive shaft projecting through one chamber wall. Projecting outwardly from that wall is a boss that defines a cylindrical cavity the axis of which coincides with that of the shaft. A roller is rotationally mounted on the shaft with its axis parallel to but offset from that of the shaft, the diameter of the roller being less than the diameter of the cavity. A resiliently-walled flexible tube runs between inlet and outlet openings in the boss and around the interior wall of the cavity with the double wall thickness of the tube being slightly greater than the minimum spacing between the interior wall and the roller. Overlying the cavity is a hinged door. The door is of transparent material so as to permit observation of the proper operation of the unit. The one chamber wall is constructed so as to form one end bell in which one end of the motor shaft is journaled. The housing accommodates a cooling fan and results in a compact structure. Coupled to one end of the flexible tube is a nozzle assembly that has a valve and valve operator manually adjustable to control the rate of fluid flow as well as serving selectively to cause cessation of that flow. The nozzle assembly is formed to include a barrel portion joined to a handgrip portion that permits ready operation by the fingers of the user.

United States Patent [191 Mullins et al.

[4 1 Oct. 14, 1975 IRRIGATION LAVAGE [75] Inventors: Keith M. Mullins, Fort Collins;

David W. Smith, Wellington; Thomas G. Cannon, Fort Collins, all of C010.

[73] Assignee: Teledyne Industries, Inc;, Teledyne Aqua Tec, Fort Collins, C010.

22 Filed: Jan. 30, 1975 21 Appl. No.: 545,731

[52] U.S. Cl. 239/102; 239/349; 239/526 [51] Int. C13... 8058 3/14; B05B 7/30; BOSB 7/02 [58] Field of Search l28/DIG. l0, 12; 239/102,

Primary ExaminerLloyd L. King Atlorney, Agent, or FirmHugh H. Drake [57] ABSTRACT An irrigation lavage is useful, for example, in wound debridement. It serves to deliver pulses of fluid under pressure. lt includes a housing that defines a chamber in which an electric motor is mounted so as to have a drive shaft projecting through one chamber wall. Projecting outwardly from that wall is a boss that defines a cylindrical cavity the axis of which coincides with that of the shaft. A roller is rotationally mounted on the shaft with its axis parallel to but offset from that of the shaft, the diameter of the roller being less than the diameter of the cavity. A resiliently-walled flexible tube runs between inlet and outlet openings in the boss and around the interior wall of the cavity with the double wall thickness of the tube being slightly greater than the minimum spacing between the interior wall and the roller. Overlying the cavity is a hinged door. The door is of transparent material so as to permit observation of the proper operationof the unit. The one chamber wall is constructed so as to form one end bell in which one end of the motor shaft is journaled. The housing accommodates a cooling fan and results in a compact structure. Coupled to one end of the flexible tube is a nozzle assembly that has a valve and valve operator manually adjustable to control the rate of fluid flow as Well as serving selectively to cause cessation of that flow. The nozzle assembly is formed to include a barrel portion joined to a handgrip portion that permits ready operation by the fingers of the user.

7 Claims, 10 Drawing Figures US. Patent Oct. 14, 1975 SheetlofZ 3,912,168

IRRIGATION LAVAGE The present invention relates to an irrigation lavage. More particularly, it pertains to apparatus for delivering pulsating jets of liquid useful, for example, in the debridement of wounds and analogous medical treatment.

For a number of years, considerable success has been experienced in connection with an oral hygiene appliance that delivers pulsating jets of water for use in cleaning the teeth and massaging the gums. Such apparatus is well known as manufactured and sold by the assignee of the present application. In addition to its oral hygiene employment, essentially the very same apparatus has undergone extensive usage in the investigation and actual application of the use of a pulsating fluid for debridement of wounds suffered by human patients. The very same appliances that had been developed for usage in homes have found their way into remote military hospitals where they were subject to the conditions of a much more demanding environment. While the appliances, thus developed for dental usage in a home environment, performed admirably in the more difficult conditions so encountered, it became apparent that desired durability and full applicability called for the development of a unit directed more precisely to the problems particularly attendant to field usage.

Perhaps naturally, the successful experience of such apparatus in the field gave rise to a corresponding interest in the development of similar apparatus for usage in hospitals and the like. A hospital locale is one which requires equipment that can withstand long usage, accommodate sterile techniques (as also in the field), and be capable of being operated by personnel inexperienced with operation of the unit itself. While the aforementioned dental hygiene appliance offered many valuable features for use either in the field or in the hospital, it did not lend itself directly to complete satisfaction of usage in such environments.

Seeking to better the situation, attention has been given to apparatus which utilizes a long-known principle for achieving the delivery of a pulsating jet of fluid. This involves the incorporation of a collapsible, fluidcarrying tube that is progressively squeezed by one or more rollers which press along the walls of the tube. Such an approach has been used in connection with the pumping of fluids ranging from milk to petroleum products. Particularly as applied to such fields as the dairy industry, pumping mechanisms of this type have proved valuable in that they allow ready removability and sterilization of the flexible tube that constitutes an important part of the pumping mechanism and which enables ready sterilization of all components of the pumping machinery that contact the milk (or other fluid) being delivered.

Such prior approaches have, indeed, led to greatly improved health, safety, efficiency and ease of maintenance. At the same time, however, they have tended to lead to the development of rather sophisticated and expensive apparatus designed to resolve what might have been a more-easily solved problem.

It is, accordingly, a general object of the present invention to provide a new and improved irrigation lavage that meets, overcomes and resolves deficiencies and difficulties attendant to apparatus of the character hereinabove mentioned.

Another object of the present invention is to provide a new and improved irrigation lavage that permits ready utilization and operating visualization of its components most significant in terms of proper usage.

A further object of the present invention is to provide a new and improved irrigation lavage which includes, as cooperative parts, active pumping elements which are sufficiently inexpensive as to enable their disposability after each usage.

An irrigation lavage constructed in accordance with the present invention includes a housing that defines an enclosed motor-receptive chamber which has continuous side walls and opposing end walls. An electric motor is mounted in the chamber and has a drive shaft that projects through one of the end walls. A boss projects outwardly from the exterior of that one end wall and defines a cylindrical cavity the axis of which coincides with that of the shaft, the boss having inlet and outlet opening defined in spaced portions of its walls. Rotationally mounted on the shaft is a roller the axis of which is parallel to but offset from that of the shaft. The diameter of the roller is less than the diameter of the cavity. A resiliently-walled flexible tube runs from the inlet opening to the outlet opening and around the interior wall of the cavity. The tube has a double wall thickness which is slightly greater than the minimum spacing between the interior wall of the cavity and the roller. A door is hinged at one side of the boss so as to close in overlying relationship to the cavity and in containment of the tube. Finally, there are means for maintaining the door closed in such overlying relationship. As oneparticular feature, the door is of transparent material. In connection with another feature, the housing is formed to have annularly continuous side walls and opposing end walls with one of those end walls being attached to the side walls and the other being integral therewith. The motor is mounted in the chamber so as to have the drive shaft projecting through the one end wall with that end wall constituting the end bell of the motor. In another aspect, a nozzle assembly is coupled to the end of the tube that extends from the outlet opening. The assembly includes a valve and a valve operator which is manually adjustable to control the rate of fluid flow through the tube and selectively to cause cessation of such flow. Furthermore, the nozzle assembly is pistol-shaped with its valve operator being exposed for operability by the fingers on the user.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The organization and manner of operation of the invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in the several figures of which like reference numerals identify like elements, and in which:

FIG. 1 is a perspective view of one embodiment of an irrigation lavage;

FIG. 2 is a side-elevational view of the apparatus shown in FIG. 1, including in dashed line a representation of the open position of a door associated therewith;

FIG. 3 is a front-elevational view of the main portion of the apparatus shown in FIG. 1;

FIG. 4 is a front-elevational view of a nozzle assembly included in the apparatus shown in FIG. 1;

FIG. 5 is a cross-sectional view taken along the line 55 in FIG. 2;

FIG. 6 is a cross-sectional view taken along the line 66 of FIG. 3;

FIG. 7 is a fragmentary cross-sectional view taken along the line 7-7 in FIG. 3;

FIG. 8 is a fragmentary cross-sectional view taken along the line 88 in FIG. 3;

FIG. 9 is a cross-sectional view taken along the line 9-9 in FIG. 4; and

FIG. 10 is an enlarged fragmentary cross-sectional view taken laterally through the apparatus as shown in FIG. 9.

An irrigation lavage 20 includes a housing 22 that has continuous side walls 24 and opposing end walls 26 and 28 which serve to define an enclosed chamber 30 receptive of an electric motor 32. Rear end wall 22 is cast integrally with side walls 24, while front end wall 28 is a separate molding removably attached so as to nest against the forward periphery of side walls 24. Motor 32 is secured to forward end wall 28 by a plurality of four spaced screws 34 that project through end wall 28 into the stator laminations of the motor. Thus, end wall 28 constitutes one end bell of motor 32. The forward end of motor drive shaft 36 projects through and is journaled in front end wall 28. At the rear end of motor 32, that end portion of drive shaft 36 projects rearwardly through a journal 38 mounted in an interior support wall 40 spaced parallel to and inwardly from rear end wall 26 of housing 22. Mounted on the extreme rear end portion of shaft 36 is a first spur gear 42 which meshes with a second spur gear 44 mounted for rotation from interior wall 40. Secured on the rear end of the shaft mounting gear 44 is a multiple-bladed fan 46. Fan 46 draws cooling air for ventilation through openings 48 formed in the bottom one of side walls 24 and exhausts that air through openings 50 formed in rear wall 26 of the housing. By using end wall 28 as one end bell for the motor, only two bearings are required to journal motor shaft 36 and the pump. End wall 28 is secured to the remainder of the housing by the fact that motor 32 is affixed to the bottom wall of the housing by resiliently-grommeted screws 51.

A carrying handle 52 projects upwardly from the top one of side walls 24, being disposed at least approximately above the center of gravity of the lavage so as to permit its being carried in its normal orientation. Parallel-spaced legs 54, enclosed across the front by an integral panel 56, project downwardly from the bottom one of walls 24 so as to form a base for the lavage, permit air to be drawn from beneath the unit into openings 48 and cause the lavage, when placed on a flat surface, to be disposed with the upper edge portion of front wall 28 tilted backwardly. In use, such tilt of the front panel permits more ready observation by the user of correct pumping action, as will be described, and also facilitates initialreadying of the lavage for operation.

Electric power-supply cord 58 enters rear wall 26 through a grommet and is wired through a switch 60 disposed with its handle projecting through an opening in front wall 28, so as to permit energization of motor 32. Projecting rearwardly from rear wall 26 is a U shaped bracket 60 to the rearwardly-flange bite of which is affixed a captivating flange 62. When the lavage is not in use, cord 58 may be coiled in place by wrapping it around bracket 60 so its coiled cord is captivated in place by flange 62. In use, bracket 60 also serves to insure that the rear of the unit is spaced from any wall or other surface that otherwise might interfere with the free flow of ventilating air.

Projecting outwardly from the exterior of front end wall 28 is a boss 64 that defines a generally-cylindrical cavity 66 the axis of the working portion of which coincides with that of shaft 36. Boss 64 is formed to define an inlet opening 68 and an outlet opening 70 defined in spaced portions of the walls of boss 64. A roller 72 is rotationally mounted on the forward end portion of shaft 36 with the axis of roller 72 being parallel to but offset from that of shaft 36. Thus, roller 72 is eccentrically mounted upon shaft 36 so as, also, to have an eccentric relationship with respect to the laterallyinterior wall of cavity 66; the working portion of the latter extends from approximately the one oclock to the seven oclock positions as determined by viewing FIG. 5. Roller 72 is journaled for rotation upon a bearing 76'having a hub that is secured off-center upon the forward end of shaft 36 by an integral screw 78.

A resiliently-walled flexible tube 80 is disposed so as to run from inlet opening 68 to outlet opening 70 and around the working interior wall of cavity 66. That is, tube 80 is disposed in the cavity between the aforesaid one oclock and seven oclock positions. The double wall thickness of tube 80 is slightly greater than the minimum spacing between that interior wall of cavity 66 and the perimeter of roller 72. When shaft 36 is in a rotational position such that eccentrically related roller 72 is relatively positioned toward the generally right-hand portion of the cavity wall, as viewed in FIG. 5, tube 80 is pinched closed. Hearing 76 provides the existence of only rolling contact between roller 72 and tube 80.

Upon energization of motor 32 so that roller 72 rotates in the counter-clockwise direction, again as illustrated in FIG. 5, the pinching action upon tube 80 repetitively moves from the vicinity of inlet opening 68 to the vicinity of outlet opening 70. In a manner known as such from the prior art such as that discussed in the introduction, the progressive pinching action serves to draw fluid into tube 80 through inlet opening 68 and discharge that fluid from the tube outwardly from outlet opening 70 in a series of pulses. The inlet and outlet openings are so located as to yield a pulsating flow as similar as possible to that from a piston-type pump.

To survive the high pressure developed and the continued wear imposed by the action of roller 72 in use, tube 80 preferably is formed of an inner flexible tube 82, of rubber or deformable plastic, covered by a sheath 84 braided from nylon or other highly-durable fibers. To save expense, however, tube 80 of such composite form preferably is limited in length to that which accommodates placement within cavity 66 so as to project outwardly from respective inlet opening 68 and outlet opening 70 only a somewhat minimum extent. At its inlet end, tube 80 is sealingly secured upon one end of a conventional nipple 86 engagable at its other end portion with a flexible plastic tube 88. As i'l'lustrated, the remote end of tube 88 is secured by a slip fit upon a conventional fitting 90 insertable through the typical stopper 92 provided in a bottle 94 containing the irrigating solution to be utilized. Such solution, for exam ple, may be sterilized water or of a saline nature. At its other end, tube 80 is joined to a flexible tube 96, typically of plastic, by a clamp 98. To insure proper placement within cavity 66 of tube 80, clamp 98 is locatingly received within a recess 100 formed as part of outlet opening 70.

A door 102 is hinged at one side of boss 64 so as to close in overlying relationship to cavity 66 and in containment of tube 80. Door 102 is maintained in its closed and overlying relationship by a thumbscrew 104 threaded into the adjacent portion of boss 64. When desired, an electrical switch may be positioned so as to be operated by closure of door 102 or locking of thumbscrew 104. The switch is connected in series with motor 32 in order to prohibit e'nergization when door 102 is open. To permit direct visual observation by the user of proper insertion and alignment of tube 80 between roller 72 and the inner wall of cavity 66, door 102 is formed ofa transparent material such as polycarbonate. As part of the hinging mechanism for door 102, boss 64 includes an elongated outwardly-projecting lug 106 in which are defined recesses 108 that accept ears 110 integrally projecting from the main panel of door 102. Respective pins 112 extend lengthwise through lugs 106 and ears 110 so as to support door 102 in a swingable manner.

Coupled to the end of tube 96 remote from tube 80 is a nozzle assembly 114. Assembly 114 includes a valve 116 and a valve operator 118. Valve operator 118 is manually adjustable so as to permit control of the rate of fluid flow through tube 96 as well as selectively to cause cessation of such fluid flow. In more detail, valve 116 preferably is molded and machined from a suitable plastic so as to include an inlet nipple 120 upon which the corresponding end of tube 96 is sealingly received, together with an inlet conduit 122 leading from nipple 120 to a valve seat 124. Beyond seat 124 is an interior barrel 126 through which is received a valve stem 128 carrying at its inner end a valve point 130 that is movable against seat 124 so as to effect valve clousre as well as flow regulation. Valve operator 118, on the inner end of which valve point 130 is formed, is threadably received within the bore of barrel 126 as indicated at 131, the engagement being sealingly completed by an O-ring 132 that encircles the inner end portion of operator 118. An outlet conduit 134 terminates at its inner endin ports which communicate with a valve chamber 136 immediately beyond valve point 130. Valve operator 118,is also formed at the outlet end of conduit 134 to include a fluid coupling 138 sealed by an O-ring 139 to a hollow stem 140 projecting rearwardly from a nozzle head 142.

Binding the entire nozzle assembly together is a continuous strap 144, which may be formed either of metal or plastic and which is so bent as to define a barrel portion 146 in which valve operator 118 is contained and a handgrip portion 148 that depends downwardly from the rear end vicinity of barrel portion 146 and from which tube 96 emerges at the bottom. Strap 144 is so formed as to leave user access to valve operator 1 18 on both lateral sides of valve assembly 114. Moreover, the exterior lateral surface of valve operator 118 preferably is knurled. Accordingly, the user is able to grasp nozzle assembly 114 in the manner of pistol and need only to utilize his thumb and forefinger in order to attain complete valving control and operation Completing the mechanical structure, strap 144 is secured to the block in which seat 124 is defined by means of screws 150.

In use, the operator installs and, if necessary, interconnects and intercouples tubes 80, 88 and 96 together with the supply such as bottle 94 and nozzle assembly 114. At least normally, all of these components will have been sterilized. Switch 60 is then thrown to its energizing position, and operation of roller 72 is observed through transparent door 102 in order to insure that proper pumping action is occurring. The user then need only grasp nozzle assembly 114 in one hand with which he is able both to stop and start the flow of liquid altogether as well as to vary the flow rate by manipulation of valve operator 118. The users other hand may be left entirely free for the purpose of manipulating instruments or the relative position or exposure of the area being treated with the pulsating fluid. Because complete flow control is included in nozzle assembly 114, the operator does not have to have access to the pumping unit. Therefore, the latter does not have to be sterilized and may be positioned out of the sterile field. In a successful adaptation, shaft 36 of motor 32 rotates at twelve hundred revolutions-per-minute. Adjustment of valve operator 1 18 permits the delivery of the liquid at a rate variable between zero and about twelvehundered milliliters per minute. Adequate ventilation within housing 22 is secured by selecting gears 42 and 44 so that fan 46 is rotated at a speed of three times that of shaft 36.

It is contemplated that all portions of lavage 20 exclusive of the different tubing and nozzle assembly 1 14 are of heavy-duty, durable construction. While tube is made to have sufficient durability so as to withstand the pressure and pumping action imposed by roller 72, even that tubing as well as tubing 88 and 96 together with nozzle assembly 114 are designed as throw-away items. While, indeed, they may be re-sterilized after a given usage, it is at least often more economical to discard them following their use in connection with a particular patient.

While a particular embodiment of the invention has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.

We claim:

1. An irrigation lavage comprising:

a housing defining an enclosed motor-receptive chamber and having continuous side walls and opposing end walls;

an electric motor mounted in said chamber and having a drive shaft projecting through one of said end walls;

a boss projecting outwardly from the exterior of said one end wall and defining a generally cylindrical cavity the axis of which coincides with that of said shaft, said boss having inlet and outlet openings defined in spaced portions of its walls;

a roller rotationally mounted on said shaft with the axis of said roller parallel to but offset from that of said shaft, the diameter of said roller being less than the diameter of said cavity;

a resiliently-walled flexible tube running from said inlet opening to said outlet opening and around the interior wall of said cavity, the double wall thickness of said tube being slightly greater than the minimum spacing between said interior wall and said roller;

a door, of transparent material, hinged at one side of said boss to close in overlying relationship to said cavity and in containment of said tube;

and means for maintaining said door closed in said overlying relationship.

2. An irrigation lavage comprising:

a housing defining an enclosed motor-receptive chamber and having integrally continuous side walls and opposing vend walls, one of said end walls being attached to said side walls and the other of said end walls being integral with said sidewalls;

an electric motor mounted in said chamber and having a drive shaft projecting through said one end wall, said one end wall constituting one end bell of said motor;

a boss projecting outwardly from the exterior of said one end wall and defining a generally cylindrical cavity the axis of which coincides with that of said shaft, said boss having inlet and outlet openings defined in spaced portions of its walls;

a roller rotationally mounted on said shaft with the axis of said roller parallel to but offset from that of said shaft, the diameter of said roller being less than the diameter of said cavity;

a resiliently-walled flexible tube running from said inlet opening to said outlet opening and around the interior wall of said cavity, the double wall thickness of said tube being slightly greater than the minimum spacing between said interior wall and said roller;

a door hinged at one side of said boss to close in overlying relationship to said cavity and in containment of said tube;

and means for maintaining said door closed in said overlying relationship.

3. An irrigation lavage as defined in claim 2 which further includes a fan mounted within said chamber, means for coupling said fan drivingly to said shaft, and means defining spaced inlet and outlet vent openings in said housing.

4. An irrigation lavage as defined in claim 2 in which said one end wall is supported exclusively from said motor, and said motor is resiliently mounted to one of said side walls,

5. An irrigation lavage comprising:

a housing defining an enclosed motor-receptive chamber and having continuous side walls and opposing end walls;

an electric motor mounted in said chamber and having a drive shaft projecting through one of said end walls;

a boss projecting outwardly from the exterior of said one end wall and defining a generally cylindrical cavity the axis of which coincides with that of said shaft, said boss having inlet and outlet openings defined in spaced portions of its walls;

a roller rotationally mounted on said shaft with the axis of said roller parallel to but offset from that of said shaft, the diameter of said roller being less than the diameter of said cavity;

a resiliently-walled flexible tube running from said inlet opening to said outlet opening and around the interior wall of said cavity, the double wall thickness of said tube being slightly greater than the minimum spacing between said interior wall and said roller;

a door hinged at one side of said boss to close in overlying relationship to said cavity;

and a nozzle assembly coupled to the end of said tube extending from said outlet opening, said assembly including a valve and a valve operator manually adjustable to control the rate of fluid flow through said tube and selectively to cause cessation of said fluid flow.

6. An irrigation lavage as defined in claim 5 in which said assembly includes a barrel portion joined to a handgrip portion downwardly depending from one end of said barrel portion, in which said assembly is coupled to said end of said tube by a flexible conduit emerging from the bottom of said hand-grip portion, and in which said valve operator is disposed in said barrel portion.

7. An irrigation lavage as defined in claim 6 in which said assembly includes a continuous strap shaped to define both of said portions, and in which said valve operator includes a finger-operable cylinder accessible between opposing side edges of said strap.

l l l 

1. An irrigation lavage comprising: a housing defining an enclosed motor-receptive chamber and having continuous side walls and opposing end walls; an electric motor mounted in said chamber and having a drive shaft projecting through one of said end walls; a boss projecting outwardly from the exterior of said one end wall and defining a generally cylindrical cavity the axis of which coincides with that of said shaft, said boss having inlet and outlet openings defined in spaced portions of its walls; a roller rotationally mounted on said shaft with the axis of said roller parallel to but offset from that of said shaft, the diameter of said roller being less than the diameter of said cavity; a resiliently-walled flexible tube running from said inlet opening to said outlet opening and around the interior wall of said cavity, the double wall thickness of said tube being slightly greater than the minimum spacing between said interior wall and said roller; a door, of transparent material, hinged at one side of said boss to close in overlying relationship to said cavity and in containment of said tube; and means for maintaining said door closed in said overlying relationship.
 2. An irrigation lavage comprising: a housing defining an enclosed motor-receptive chamber and having integrally continuous side walls and opposing end walls, one of said end walls being attached to said side walls and the other of said end walls being integral with said sidewalls; an electric motor mounted in said chamber and having a drive shaft projecting through said one end wall, said one end wall constituting one end bell of said motor; a boss projecting outwardly from the exterior of said one end wall and defining a generally cylindrical cavity the axis of which coincides with that of said shaft, said boss having inlet and outlet openings defined in spaced portions of its walls; a roller rotationally mounted on said shaft with the axis of said roller parallel to but offset from that of said shaft, the diameter of said roller being less than the diameter of said cavitY; a resiliently-walled flexible tube running from said inlet opening to said outlet opening and around the interior wall of said cavity, the double wall thickness of said tube being slightly greater than the minimum spacing between said interior wall and said roller; a door hinged at one side of said boss to close in overlying relationship to said cavity and in containment of said tube; and means for maintaining said door closed in said overlying relationship.
 3. An irrigation lavage as defined in claim 2 which further includes a fan mounted within said chamber, means for coupling said fan drivingly to said shaft, and means defining spaced inlet and outlet vent openings in said housing.
 4. An irrigation lavage as defined in claim 2 in which said one end wall is supported exclusively from said motor, and said motor is resiliently mounted to one of said side walls.
 5. An irrigation lavage comprising: a housing defining an enclosed motor-receptive chamber and having continuous side walls and opposing end walls; an electric motor mounted in said chamber and having a drive shaft projecting through one of said end walls; a boss projecting outwardly from the exterior of said one end wall and defining a generally cylindrical cavity the axis of which coincides with that of said shaft, said boss having inlet and outlet openings defined in spaced portions of its walls; a roller rotationally mounted on said shaft with the axis of said roller parallel to but offset from that of said shaft, the diameter of said roller being less than the diameter of said cavity; a resiliently-walled flexible tube running from said inlet opening to said outlet opening and around the interior wall of said cavity, the double wall thickness of said tube being slightly greater than the minimum spacing between said interior wall and said roller; a door hinged at one side of said boss to close in overlying relationship to said cavity; and a nozzle assembly coupled to the end of said tube extending from said outlet opening, said assembly including a valve and a valve operator manually adjustable to control the rate of fluid flow through said tube and selectively to cause cessation of said fluid flow.
 6. An irrigation lavage as defined in claim 5 in which said assembly includes a barrel portion joined to a handgrip portion downwardly depending from one end of said barrel portion, in which said assembly is coupled to said end of said tube by a flexible conduit emerging from the bottom of said hand-grip portion, and in which said valve operator is disposed in said barrel portion.
 7. An irrigation lavage as defined in claim 6 in which said assembly includes a continuous strap shaped to define both of said portions, and in which said valve operator includes a finger-operable cylinder accessible between opposing side edges of said strap. 